Power converter using multiple phase-shifting quasi-resonant converters

• US 8,842,450 B2
• Filed: 04/12/2011
• Issued: 09/23/2014
• Est. Priority Date: 04/12/2011
• Status: Active Grant

• Current Assignee: MyPAQ Holdings Ltd. (Transpacific IP Group Limited)
• Original Assignee: Flextronics America LLC (Flextronics International Limited)
• Inventors: Jungreis, Aaron, Brinlee, Antony, Garrity, Paul
• Primary Examiner(s): Laxton, Gary L
• Assistant Examiner(s): Torres-Rivera, Alex
• Application Number:
  US13/085,393
• Publication Number:
  US 20120262953A1
• Time in Patent Office: 1,260 Days
• Field of Search: 363/21.02, 363/21.03, 363/65, 363/71, 363/95, 363/97, 363/131
• US Class Current: 363/21.03
• CPC Class Codes: H02M 1/0058 by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero using an auxiliary actively switched resonant commutation circuit connected to an intermediate DC voltage or between two push-pull branches of an inverter bridge H02M7/4811; in resonant inverters H02M7/4815; in inverters operating from a resonant DC source H02M7/4826
• CPC Class Codes: H02M 3/01 Resonant DC/DC converters
• CPC Class Codes: H02M 3/285 Single converters with a plurality of output stages connected in parallel parallel operation of a plurality of converters in dc distribution networks H02J1/10
• CPC Class Codes: H02M 3/33571 Half-bridge at primary side of an isolation transformer
• CPC Class Codes: H02M 3/33573 Full-bridge at primary side of an isolation transformer
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier

Abstract

A resonant power converter draws current from a source that provides a supply current. Multiple quasi-resonant converters are interleaved and each quasi-resonant converter receives the supply current and forms a phase-shifted current according to drive signals supplied by a controller. Each phase-shifted current includes a dead-time delay and is phase-shifted relative to the other phase-shifted currents. The dead-time delay is determined as a time value within a calculated dead-time delay range having a dead-time delay minimum and a dead-time delay maximum. The outputs of each quasi-resonant converter are added together thereby reducing the AC components of current. Two, three, or four quasi-resonant power converters can be interleaved, each forming phase-shifted currents that are phase-shifted relative to the other phase-shifted currents.

Claims

1. A power converter comprising:

a. an input power supply configured to provide a supply current;

b. a plurality of quasi-resonant converters each comprising a plurality of switches and coupled in parallel to the input power supply such that the supply current is input to each of the plurality of quasi-resonant converters;

c. a controller coupled to the plurality of switches of each of the plurality of quasi-resonant converters, wherein the controller is configured to operate with a dead-time delay and to generate independent drive signals that include the dead-time delay, the drive signals are selectively output to each of the plurality of switches of the plurality of quasi-resonant converters, wherein each of the plurality of switches of the plurality of quasi-resonant converters is configured to receive one or more of the drive signals and to form a modified supply current in response to the received one or more drive signals thereby forming a plurality of modified supply currents, wherein the modified supply current of each of the plurality of quasi-resonant converters includes the dead-time delay and is phase-shifted relative to each other modified supply current of the plurality of modified supply currents, further wherein the plurality of quasi-resonant converters are configured to perform a power conversion function on the plurality of modified supply currents, further wherein the dead-time delay is substantially a midpoint between a minimum dead-time period that still enables zero voltage switching of the plurality of switches and a maximum dead-time period that still enables zero voltage switching of the plurality of switches; and

d. an output capacitor coupled to an output side of each of the plurality of quasi-resonant converters.

2. The power converter of claim 1 wherein each of the plurality of quasi-resonant converters is configured to operate at the same switching frequency.

3. The power converter of claim 1 wherein each of the plurality of quasi-resonant converters comprises a quasi-resonant tank and a transformer.

4. The power converter of claim 3 wherein at least one leg of each transformer is shared by all transformers.

5. The power converter of claim 3 wherein each of the plurality of quasi-resonant converters further comprises a rectifier circuit coupled between an output side of the transformer and the output capacitor.

6. The power converter of claim 1 further comprising a filter coupled to the input power supply, wherein the filter is configured to receive a power supply signal and to output the supply current to each of the multiple quasi-resonant converters.

7. The power converter of claim 1 wherein each of the plurality of quasi-resonant converters comprises one of the group consisting of a series quasi-resonance circuit, a parallel quasi-resonance circuit, and a series-parallel quasi-resonance circuit.

8. The power converter of claim 1 wherein each of the plurality of quasi-resonant converters comprises one of the group consisting of a half-bridge quasi-resonant converter, a full-bridge quasi-resonant converter, and a push-pull quasi-resonant converter.

9. The power converter of claim 1 wherein each of the plurality of quasi-resonant converters are configured as a buck-type converter.

10. The power converter of claim 1 wherein the plurality of quasi-resonant converters comprise three quasi-resonant converters, and the plurality of modified supply currents comprise a first modified supply current formed by a first quasi-resonant converter, a second modified supply current formed by a second quasi-resonant converter and phase-shifted substantially 60 degrees relative to the first modified supply current, and a third modified supply current formed by a third quasi-resonant converter and phase-shifted substantially 120 degrees relative to the first modified supply current.

11. The power converter of claim 1 wherein the plurality of quasi-resonant converters comprise two quasi-resonant converters, and the plurality of modified supply currents comprise two supply currents including a first modified supply current formed by a first quasi-resonant converter, and a second modified supply current formed by a second quasi-resonant converter and phase-shifted substantially 90 degrees relative to the first supply current.

12. The power converter of claim 1 wherein the plurality of quasi-resonant converters comprise four quasi-resonant converters, and the plurality of modified supply currents comprise a first modified supply current formed by a first quasi-resonant converter, a second modified supply current formed by a second quasi-resonant converter, a third modified supply current formed by a third quasi-resonant converter, and a fourth modified supply current formed by a fourth quasi-resonant converter.

13. The power converter of claim 1 wherein the midpoint is identified by the controller.

14. The power converter of claim 1 wherein the controller always utilizes the midpoint as the dead-time delay.

15. A power converter comprising:

a. an input power supply configured to provide a supply current;

b. a plurality of quasi-resonant converters coupled in parallel to the input power supply such that the supply current is input to each of the plurality of quasi-resonant converters;

c. a controller coupled to the plurality of quasi-resonant converters, wherein the controller is configured to operate with a dead-time delay and to generate independent drive signals that include the dead-time delay, the drive signals are selectively output to each of the plurality of the quasi-resonant converters, wherein each of the plurality of quasi-resonant converters is configured to receive one or more of the drive signals and to form a modified supply current in response to the received one or more drive signals thereby forming a plurality of modified supply currents, wherein the modified supply current of each of the plurality of the quasi-resonant converters includes the dead-time delay and is phase-shifted relative to each other modified supply current, further wherein the plurality of quasi-resonant converters are configured to perform a power conversion function on the plurality of modified supply currents, further wherein the dead-time delay is substantially a midpoint between a maximum time delay that enables a zero crossing and a minimum time delay that enables a zero crossing; and

d. an output capacitor coupled to an output side of each of the plurality of quasi-resonant converters;

wherein the plurality of quasi-resonant converters comprise four quasi-resonant converters, and the plurality of modified supply currents comprise a first modified supply current formed by a first quasi-resonant converter, a second modified supply current formed by a second quasi-resonant converter and phase-shifted substantially 45 degrees relative to the first modified supply current, a third modified supply current formed by a third quasi-resonant converter and phase-shifted substantially 90 degrees relative to the first modified supply current, and a fourth modified supply current formed by a fourth quasi-resonant converter and phase-shifted substantially 135 degrees relative to the first modified supply current.